1. Field of the Invention
The present invention relates to a novel antitumor antibiotic designated herein as BMY-41339 and to its preparation by fermentation of a BMY-41339-producing strain of Actinomadura verrucosospora.
2. Description of the Prior Art
BMY-41339 is a newly discovered bioactive compound of the BBM-1675 complex disclosed in U.S. Pat. No. 4,675,187. That patent discloses fermentation of Actinomadura verrucosospora strain H964-92 (ATCC 39334) or Actinomadura verrucosospora strain A1327Y (ATCC 39638) to produce a complex of potent antibiotic substances designated BBM-1675 complex and the separation of this complex into two major bioactive components, BBM-1675 A.sub.1 and A.sub.2, and four minor components, BBM-1675 A.sub.3, A.sub.4, B.sub.1 and B.sub.2.
U.S. Pat. No. 4,530,835 discloses fermentation of Streptomvces sp. ATCC 39363 to produce the antitumor antibiotics designated CL-1577 A and B. The producing microorganism, ATCC 39363, is renamed Actinomadura verrucaspora subspecies veractimYcin in U.S. Pat. No. 4,615,975. BBM-1675 A.sub.1 and A.sub.2 are believed to be identical respectively, to CL-1577 A and B.
J. Antibiotics 38 (11): 1605-1609 (1985) discloses isolation of another antitumor antibiotic, BBM-1675 A.sub.1b, from the fermentation broth of Actinomadura verrucosospora strain H964-62 (ATCC 39334). It is believed that component A.sub.1b is identical to the antitumor antibiotic WS 6049-A disclosed in U.S. Pat. 4,578,271 as being produced by fermentation of Actinomadura pulveraceus ATCC 39100. WS 6049-A and B are related in structure to BBM-1675 A.sub.1 and A.sub.2.
The structures of BBM-1675 Al, A.sub.2 and A.sub.1b have been elucidated and are disclosed in J. Am. Chem. Soc. 109:3462-3464 (1987). They are characterized by an unusual conjugated di-yne moiety which has also been found in the calichemicins (J. Am. Chem. Soc. 109:3466-3468, 1987) produced by a micromonospora strain (Program and Abstracts of 26th Interscience Conference on Antimicrobial Agents and Chemotherapy, Sept. 1986, Abstract 227).
A fragment of CL-1577 A or B designated CL-1577-B.sub.4 is disclosed in U.S. Pat. 4,661,353 while fragments of BBM-1675 A.sub.1 or A.sub.2 designated BBM-1675 C and D are disclosed in U.K. Published Application 2,179,649 A.
Co-pending application Ser. No. 208,330 filed June 10, 1988 discloses the antitumor antibiotic designated BU-3420T having the formula ##STR1## produced by fermentation of Micromonospora chersina ATCC 53710 and its triacetate derivative.